Excess Mortality Due to Pneumonia or Influenza During Influenza Seasons Among Persons With Acquired Immunodeficiency Syndrome

Abstract
INFLUENZA CAUSES significant morbidity and mortality in various high-risk groups, including persons with chronic cardiopulmonary disease, diabetes mellitus, and advanced age and those residing in long-term care facilities. However, there is limited information concerning the impact of influenza on morbidity and mortality in persons with human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS). Previous reports1,2 suggested that influenza may severely compromise respiratory function and cause prolonged duration of illness in patients with HIV infection, but, until recently, information regarding the impact of influenza on this patient population has been largely anecdotal.1-5 Because of potential for substantial benefit, the Advisory Committee on Immunization Practices since 1987 has recommended that HIV-infected individuals receive routine vaccination against influenza.6,7 However, this policy has been somewhat controversial,8 and its implementation in clinical settings has not been widespread, as demonstrated by low vaccination rates.9 Barriers to successful vaccination efforts may include uncertainties regarding immunogenicity of the vaccine in patients with HIV infection10-15 and implications of possible transient increases in HIV viral load following vaccination.13-21 Perhaps one of the largest influences on the poor rates of immunization has been the persistent uncertainties concerning the magnitude of risk posed by influenza among persons with AIDS or HIV infection. For this reason, we conducted this study to assess influenza-related excess mortality in persons with AIDS.